Oracle Database 1Z0-071 Glossary: SQL and Schema Terms
March 31, 2026
Oracle Database 1Z0-071 glossary of SQL, joins, subqueries, DML, and schema terms.
Use this glossary to clean up high-confusion SQL language fast. This exam gets easier when you keep row flow, null behavior, grouping, and set logic in separate mental buckets.
High-value terms
| Term |
What to remember |
| aggregation |
combining multiple rows into summary output with functions such as COUNT, SUM, or AVG |
| correlated subquery |
a subquery that depends on values from the current outer-query row |
| group |
the set of rows that share the same GROUP BY keys before aggregation |
HAVING |
a filter applied after grouping and aggregation |
| inner join |
a join that returns only matching rows from both sides |
| null semantics |
the rules that govern how NULL behaves in comparisons, predicates, and set logic |
| outer join |
a join that preserves unmatched rows from one side |
| predicate |
a condition that evaluates to true, false, or unknown |
| set operator |
a query combiner such as UNION, UNION ALL, INTERSECT, or MINUS |
| transaction |
a unit of work that ends with COMMIT or ROLLBACK |
Common confusion pairs
| Pair |
Keep this distinction clear |
WHERE vs HAVING |
WHERE filters rows before grouping; HAVING filters groups after aggregation |
IN vs EXISTS |
membership test versus existence test |
NOT IN vs NOT EXISTS |
NOT IN can misbehave when nulls appear; NOT EXISTS is often safer |
| inner join vs outer join |
remove non-matches versus preserve one side |
UNION vs UNION ALL |
remove duplicates versus keep duplicates |
COUNT(*) vs COUNT(column) |
count all rows versus count only non-null values in that expression |
Fast recall anchors
| If you see… |
Think… |
| “wrong row count” |
join grain or duplicate amplification |
| “outer join lost rows” |
predicate placement, especially WHERE on the non-preserved side |
| “anti-match returned nothing” |
check nullable values and NOT IN behavior |
| “wrong totals” |
row shape before grouping |
| “aggregate filter” |
HAVING, not WHERE |
If three terms blur together
| Blurry group |
Reset with this rule |
WHERE, HAVING, ON |
row filtering, group filtering, and join-match logic are different stages |
IN, EXISTS, NOT EXISTS |
membership, existence, and anti-match are not interchangeable |
| inner join, outer join, Cartesian effect |
match-only rows, preserved rows, and multiplied rows are different result shapes |
NULL, equality, unknown |
null does not behave like an ordinary comparable value |
Route next
| Need |
Go here next |
| weekly pacing and weak-lane repair |
Study Plan |
join, NULL, and grouping tie-breaks |
Cheat Sheet |
| last-week decision cleanup |
FAQ |
| official Oracle sources |
Resources |
Revised on Sunday, May 10, 2026